atmosphere Article Mapping Climate Change, Natural Hazards and Tokyo’s Built Heritage Peter Brimblecombe 1,2,3,* , Mikiko Hayashi 4 and Yoko Futagami 5 1 School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong 2 Department of Marine Environment and Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan 3 Aerosol Science Research Center, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan 4 Center for Conservation Science, National Institutes for Cultural Heritage Tokyo National Research Institute for Cultural Properties, Tokyo 110-8713, Japan; [email protected] 5 Department of Art Research, Archives and Information Systems, Tokyo National Research Institute for Cultural Properties, Tokyo 110-8713, Japan; [email protected] * Correspondence: [email protected] Received: 26 May 2020; Accepted: 24 June 2020; Published: 28 June 2020 Abstract: Although climate change is well recognised as an important issue in Japan, there has been little interest from scientists or the public on the potential threat it poses to heritage. The present study maps the impact of emerging pressures on museums and historic buildings in the Tokyo Area. We examine a context to the threat in terms of fluctuating levels of visitors as a response to environmental issues, from SARS and COVID-19, through to earthquakes. GIS mapping allows a range of natural and human-induced hazards to be expressed as the spatial spread of risk. Temperature is increasing and Tokyo has a heat island which makes the city hotter than its surroundings. This adds to the effects of climate change. Temperature increases and a decline in relative humidity alter the potential for mould growth and change insect life cycles. The region is vulnerable to sea level rise, but flooding is also a likely outcome of increasingly intense falls of rain, especially during typhoons. Reclamation has raised the risk of liquefaction during earthquakes that are relatively frequent in Japan. Earthquakes cause structural damage and fires after the rupture of gas pipelines and collapse of electricity pylons. Fires from lightning strikes might also increase in a future Tokyo. These are especially relevant, as many Japanese heritage sites use wood for building materials. In parallel, more natural landscapes of the region are also affected by a changing climate. The shifting seasons already mean the earlier arrival of the cherry blossom and a later arrival of autumn colours and a lack of winter snow. The mapping exercise should highlight the spatial distribution of risk and the way it is likely to change, so it can contribute to longer term heritage management plans. Keywords: earthquakes; fire; floods; historic sites; landslides; museums; insects; sea level rise; typhoons; visitors 1. Introduction Our heritage is under threat. The need to protect Japanese tangible heritage from disasters has been addressed by government funding increases: JPY 2905 million in 2019, to JPY 3907 million in 2020. While natural hazards are well recognised issues in Japan and climate science is strong, there has been relatively little interest there from scientists or the public on the potential threat a changing climate poses on heritage, especially in the way they alter the frequency of meteorologically driven hazards. The present study maps the impact of external pressures on museums, historic buildings such as temples and shrines in the Tokyo Area. This is one of the most populous metropolitan areas in the world, which includes several prefectures of the Kanto¯ Region of Japan, as well as Yamanashi Atmosphere 2020, 11, 680; doi:10.3390/atmos11070680 www.mdpi.com/journal/atmosphere Atmosphere 2020, 11, 680 2 of 18 meteorologically driven hazards. The present study maps the impact of external pressures on museums, historic buildings such as temples and shrines in the Tokyo Area. This is one of the most populousAtmosphere 2020 metropolitan, 11, 680 areas in the world, which includes several prefectures of the Kantō Region2 of 16 of Japan, as well as Yamanashi Prefecture. The Tokyo Metropolis is elongated from east to west, stretchingPrefecture. from The Tokyomountains Metropolis which isstand elongated in the from west east to toTokyo west, Bay stretching to islands from scattered mountains over which the Pacificstand inOcean; the west although to Tokyo in this Bay study to islands islands scattered are excluded, over the yet Pacific it still Ocean; covers althoughan area of in some this study1790 squareislands kilometres. are excluded, The yet Japan it still Meteorological covers an area Agency of some (JMA) 1790 square places kilometres. 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Source: Source: National National Land Land NumericalNumerical Information Information (https://nlftp.mlit.go.jp/ (https://nlftp.mlit.go.jp/[2][2]) (c ()c )Topography Topography of of the the Tokyo Tokyo region region discussed discussed in in this paper, with a white line denoting the boundary of the Tokyo Area. this paper, with a white line denoting the boundary of the Tokyo Area. Tokyo, as a major city with a lengthy history, has a great wealth of heritage. There are numerous historic buildings and sites shrines, temples and great buildings, perhaps some favourites being: (i) Asakusa Shrine, (ii) Tog¯ u¯ Palace, (iii) Tokyo Station, (iv) Senso-ji¯ Niten-mon, (v) Nezu Shrine, (vi) Enyuu-ji Temple, (vii) Former Iwasaki House, (viii) Eitai Bridge, (ix) Shofuku-ji Temple Jizod¯ o.¯ Add to this many historic buildings; these marked as 83 points in pink (Figure2a,b) and all of them are designated buildings and structures as National Treasure or Important Cultural Properties. Tokyo has hundreds of museums and galleries, some of the favourites being: (i) Tokyo National Museum, (ii) Edo-Tokyo Museum, (iii) Ghibli Museum, (iv) Nezu Museum, (v) Hara Museum of Contemporary Art, (vi) Mori Art Museum, (vii) Tokyo Metropolitan Art Museum, (viii) National Museum of Western Art, and (ix) the National Museum of Emerging Science and Innovation. Museums are marked as 232 points in green (Figure2a,c). Maps of heritage and the risk imposed by climate change are often seen as important tools for the strategic management of heritage, e.g., [3,4], with some at a national or regional level [5–8]. Among a few examples of Japanese studies in this field, [9,10] integrated a database of the nationally designated cultural properties and a map of the active faults with GIS to estimate the seismic risk of each property. Difficulties in such mapping involve the problem of scaling because data are typically collected at national or regional levels rather than at city scale. It is also problematic to tune the data, often collected for other purposes, to heritage; e.g., seismic risk is defined for buildings in general, not heritage, or that meteorological information is collected for many purposes, so the risks imposed on heritage requires considering the notion of heritage climate [3,11]. Special threats to the region are flooding and the increased pressures that climate change may present in terms of both river and sea floods [12,13] and the failure of sea defences [14]. As Tokyo is a coastal city, sea level rise makes low lying areas additionally vulnerable to increased flooding, Atmosphere 2020, 11, 680 3 of 16 with Estaban et al. [15], arguing that “The combined effect of an increase in typhoon intensity and sea level rise could pose significant challenges to coastal defences around Tokyo Bar around the turn of the twenty-first century.” There are also risks from earthquakes, which are regularly mapped in the city as this affects a range of issues in addition to the threat to built heritage, e.g., real estate prices [16].